华池-白豹地区长6油层组储层评价

华池-白豹地区长6油层组是重要的勘探目的层,其砂体发育,含油性较好,但储层物性差,均为低渗、特低渗透储层,是典型岩性—地层油藏.在岩心和沉积相分析的基础上,对大量砂岩样品进行铸体薄片、扫描电镜、X-衍射、压汞分析,结合测井、地震资料,对华池-白豹地区长6储层特征进行综合研究,认为长6储层岩石以细—极细粒长石砂岩为主,胶结物主要为粘土及碳酸盐岩,孔隙类型以原生粒间空隙为主,属于低-特低孔隙度,特低-超低渗储层.影响储层物性的主要因素有碎屑颗粒大小及结构、胶结物类型及含量、孔隙类型、成岩作用和沉积相类型.研究区长6油层组储层总体上以Ⅲ类(差)储层为主.

Reservoir Evaluation of Chang 6 Member in Baibao-Huachi Region, Ordos Basin

The Chang 6 Member,a typical lithologic-formation reservoir,is one of main target formations for oil/gas exploration in Huachi-Baibao region,has prominent characteristics of sandstone body development,high oil-bearing content,poor reservoir property,which all belong to low and extra-low permeable reservoirs.In this paper,based on the analysis of core and sedimentary facies,many sandstone samples were analyzed by casting thin sections,scanning electron microscope,cathodoluminescence and X-ray diffraction.The diagenesis of Chang 6 sandstone was systematically studied.The results show that the lithology of the Chang 6 reservoir is mainly the fine-very fine grain of feldspar sandstone.The cement is clay and carbonate,the pore type is mainly dominated by primary porosity,belongs to extremely low-super low permeability reservoir.The principal influencing factors are particle size,structure,type and content of cement,pore type,diagenesis and sedimentary facies type.The Chang 6 oil-generated reservoir belongs mainly to the class III(poor) reservoir.